TC Leepi/Emong - East China Sea // TD Fabian - South China Sea

Japan Meteorological Agency
Tropical Cyclone Advisory #31
TROPICAL STORM WASHI (T1121)
15:00 PM JST December 17 2011
===============================

SUBJECT: Category One Typhoon in Sulu Sea

At 6:00 AM UTC, Tropical Storm Washi (996 hPa) located at 9.1N 121.6E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving west at 13 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
180 NM from the center in northern quadrant
90 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 9.3N 116.2E - 45 knots (CAT 1/Tropical Storm)
48 HRS: 8.6N 112.4E - 40 knots (CAT 1/Tropical Storm)
72 HRS: 7.4N 108.4E - 35 knots (CAT 1/Tropical Storm)

Philippine Atmospherical Geophysical Astronomical Services and Administration
Tropical Cyclone Bulletin #10
TROPICAL STORM SENDONG (WASHI)
5:00 PM PhST December 17 2011
=================================

Tropical Storm "SENDONG" has slightly weakened as it continues to move towards Palawan

At 4:00 PM PhST, Tropical Storm Sendong located at 9.2°N 121.1°E or 220 km west of Dumaguete City has 10 minute sustained winds of 35 knots with gusts of 45 knots. The cyclone is reported as moving west at 12 knots.

Signal Warnings
===============

Signal Warning #2
-----------------

Luzon region
============
1.Palawan

Signal Warning #1
----------------

Luzon region
============
1.Cuyo
2.Coron Group of Island

Visayas region
=============
1.Southern Negros

Additional Information
========================

All signals elsewhere are now lowered.

Residents in low lying and mountainous areas under Public Storm Warning Signals are alerted against possible flash floods and landslides. Likewise, those living in coastal areas are alerted against big waves or storm surges generated by this tropical cyclone.

Estimated rainfall amount is from 10-20 mm per hour (heavy) within the 300 km diameter of the Tropical Storm.

Fishing boats and other small sea crafts are advised not to venture out into the sea.

The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 11 PM today and the hourly updates.

Japan Meteorological Agency
Tropical Cyclone Advisory #32
TROPICAL STORM WASHI (T1121)
18:00 PM JST December 17 2011
===============================

SUBJECT: Category One Typhoon in Sulu Sea

At 9:00 AM UTC, Tropical Storm Washi (996 hPa) located at 9.2N 121.1E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving west at 11 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
180 NM from the center in northern quadrant
90 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 9.5N 116.2E - 45 knots (CAT 1/Tropical Storm)
45 HRS: 8.6N 112.4E - 40 knots (CAT 1/Tropical Storm)
69 HRS: 7.4N 108.4E - 35 knots (CAT 1/Tropical Storm)

Japan Meteorological Agency
Tropical Cyclone Advisory #33
TROPICAL STORM WASHI (T1121)
21:00 PM JST December 17 2011
===============================

SUBJECT: Category One Typhoon in Sulu Sea

At 12:00 PM UTC, Tropical Storm Washi (996 hPa) located at 9.4N 120.6E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving west northwest at 10 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
180 NM from the center in northern quadrant
90 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 9.5N 115.6E - 40 knots (CAT 1/Tropical Storm)
45 HRS: 8.0N 111.1E - 35 knots (CAT 1/Tropical Storm)
69 HRS: 6.5N 107.2E - 35 knots (CAT 1/Tropical Storm)

RSMC Reunion
Tropical Cyclone Outlook
15:00 PM RET December 17 2011
=================================

A 1005 hPa low has formed over the last 24 hours and is located at 10:30Z near 28.4S 71.7E. According to ASCAT data from last night and this morning, 30-35 kt winds are present within a large southwestern sector of the system up to 150 to 250 NM from the center, mainly due to the strong gradient with the subtropical highs. Deep convection developed temporarily last night and this morning close to the center, but is fading away right now. This system is weakening and becoming fully extra-tropical as it moves generally southeastwards.

All available guidance suggest that a new low should form Sunday night or Monday morning in the area between 23S/26S and 48E/51E or southeast of Madagascar. If this cyclogenesis seems to be due to baroclinic factors (enhanced instability with a mid to upper level cold low over low level warm air), it appears likely that this low could gain thereafter some subtropical characteristics (ie tropical and non tropical influences) as it should move over rather warm waters between 24°C and 27°C and a temporarily weak shear under the upper level trough.

Regardless of the nature of this system, it should be associated with strong winds (30-35 kt likely at
least in the southern semi-circle with the gradient effect) and broad instability between Madagascar and the Mascareignes islands (La Reunion - Mauritius)

For the next 72 hours, there is no potential for the development of a tropical depression. However the potential for the development of a subtropical low is fair

Japan Meteorological Agency
Tropical Cyclone Advisory #35
TROPICAL STORM WASHI (T1121)
3:00 AM JST December 18 2011
===============================

SUBJECT: Category One Typhoon in Sulu Sea

At 18:00 PM UTC, Tropical Storm Washi (996 hPa) located at 10.1N 119.3E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving west northwest at 14 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
180 NM from the center in northern quadrant
90 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 9.9N 114.1E - 40 knots (CAT 1/Tropical Storm)
48 HRS: 7.5N 110.0E - 35 knots (CAT 1/Tropical Storm)
72 HRS: 5.0N 106.9E - Tropical Depression

Japan Meteorological Agency
Tropical Cyclone Advisory #36
TROPICAL STORM WASHI (T1121)
6:00 AM JST December 18 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 21:00 PM UTC, Tropical Storm Washi (996 hPa) located at 10.3N 118.5E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving west northwest at 13 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
180 NM from the center in northern quadrant
90 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 10.1N 113.2E - 40 knots (CAT 1/Tropical Storm)
45 HRS: 7.5N 110.0E - 35 knots (CAT 1/Tropical Storm)
69 HRS: 5.0N 106.9E - Tropical Depression

Philippine Atmospherical Geophysical Astronomical Services and Administration
Tropical Cyclone Bulletin #12
TROPICAL STORM SENDONG (WASHI)
5:00 AM PhST December 18 2011
=================================

Tropical Storm "SENDONG" has made another landfall in the vicinity of Puerto Princesa City and is now heading towards the West Philippine Sea

At 4:00 AM PhST, Tropical Storm Sendong located at 9.9°N 118.4°E or 60 km west northwest of Puerto Princesa City has 10 minute sustained winds of 35 knots with gusts of 40 knots. The cyclone is reported as moving west at 12 knots.

Signal Warnings
===============

Signal Warning #2
-----------------

Luzon region
============
1.Palawan

Signal Warning #1
----------------

Luzon region
============
1.Cuyo
2.Coron Group of Island

Additional Information
========================

Residents in low lying and mountainous areas under Public Storm Warning Signals are alerted against possible flash floods and landslides. Likewise, those living in coastal areas are alerted against big waves or storm surges generated by this tropical cyclone.

Estimated rainfall amount is from 10-20 mm per hour (heavy) within the 300 km diameter of the Tropical Storm.

Fishing boats and other small sea crafts are advised not to venture out into the sea.

The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 11 AM today and the hourly updates.

Japan Meteorological Agency
Tropical Cyclone Advisory #37
TROPICAL STORM WASHI (T1121)
9:00 AM JST December 18 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 0:00 AM UTC, Tropical Storm Washi (996 hPa) located at 10.3N 117.7E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving west at 15 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
180 NM from the center in northern quadrant
90 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 9.7N 112.6E - 35 knots (CAT 1/Tropical Storm)
45 HRS: 6.7N 108.4E - Tropical Depression

Additional Information
=====================

Tropical storm will move the same speed for the next 48 hours

Tropical storm will move westward for next 12 hours then move west southwestward

Tropical storm will keep present intensity for next 24 hours

Final initial Dvorak will be T1.5 after 24 hours

Philippine Atmospherical Geophysical Astronomical Services and Administration
Tropical Cyclone Bulletin #13
TROPICAL STORM SENDONG (WASHI)
11:00 AM PhST December 18 2011
=================================

Tropical Storm "SENDONG" continues to move westward in the West Philippine Sea and is expected to exit PAR tonight

At 10:00 AM PhST, Tropical Storm Sendong located at 10.4°N 116.8°E or 230 km west northwest of Puerto Princesa City has 10 minute sustained winds of 35 knots with gusts of 40 knots. The cyclone is reported as moving west at 12 knots.

Signal Warnings
===============

Signal Warning #1
----------------

Luzon region
============
1.Palawan

Additional Information
========================

Public Storm Warning Signals elsewhere are now lowered.

Residents in low lying and mountainous areas under Public Storm Warning Signals are alerted against possible flash floods and landslides. Likewise, those living in coastal areas are alerted against big waves or storm surges generated by this tropical cyclone.

Estimated rainfall amount is from 10-15 mm per hour (heavy) within the 300 km diameter of the Tropical Storm.

Fishing boats and other small sea crafts are advised not to venture out into the sea.

The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 5 PM today and the hourly updates.

Japan Meteorological Agency
Tropical Cyclone Advisory #38
TROPICAL STORM WASHI (T1121)
12:00 PM JST December 18 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 3:00 AM UTC, Tropical Storm Washi (998 hPa) located at 10.2N 116.4E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving west at 17 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
150 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 9.2N 111.5E - 35 knots (CAT 1/Tropical Storm)
45 HRS: 6.7N 108.4E - Tropical Depression

Japan Meteorological Agency
Tropical Cyclone Advisory #39
TROPICAL STORM WASHI (T1121)
15:00 PM JST December 18 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 6:00 AM UTC, Tropical Storm Washi (998 hPa) located at 10.3N 115.6E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving west at 17 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
150 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 8.6N 110.4E - 35 knots (CAT 1/Tropical Storm)
48 HRS: 5.2N 106.7E - Tropical Depression

Philippine Atmospherical Geophysical Astronomical Services and Administration
Tropical Cyclone Bulletin #14
TROPICAL STORM SENDONG (WASHI)
5:00 PM PhST December 18 2011
=================================

Tropical Storm "SENDONG" continues to move away from the country

At 4:00 PM PhST, Tropical Storm Sendong located at 10.3°N 114.9°E or 410 km west northwest of Puerto Princesa City has 10 minute sustained winds of 35 knots with gusts of 40 knots. The cyclone is reported as moving west at 12 knots.

Additional Information
========================

Public Storm Warning Signals elsewhere are now lowered.

Fishing boats and other small sea crafts over the seaboards of Luzon and Eastern Visayas are advised not to venture out into the sea due to big waves generated by Monsoon Surge enhanced by TS SENDONG and extra caution over the sea board of Western Visayas.

Residents over the Eastern section of Luzon and Eastern Visayas are alerted against possible flash floods and landslides

The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 11 PM today and the hourly updates.

Japan Meteorological Agency
Tropical Cyclone Advisory #40
TROPICAL STORM WASHI (T1121)
18:00 PM JST December 18 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 9:00 AM UTC, Tropical Storm Washi (1000 hPa) located at 10.2N 115.3E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving west at 14 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
120 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 8.4N 110.1E - 35 knots (CAT 1/Tropical Storm)
45 HRS: 5.2N 106.7E - Tropical Depression

Japan Meteorological Agency
Tropical Cyclone Advisory #41
TROPICAL STORM WASHI (T1121)
21:00 PM JST December 18 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 122:00 PM UTC, Tropical Storm Washi (1000 hPa) located at 10.2N 115.0E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving west at 13 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
120 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 8.2N 109.8E - 35 knots (CAT 1/Tropical Storm)
48 HRS: 5.7N 107.0E - Tropical Depression

RSMC Reunion
Tropical Cyclone Outlook
15:00 PM RET December 18 2011
=================================

The low at 1005 hPa, which has developed over the last 48 hours between 70E to 80E, crossed the 30 South parallel last night. It became fully extra-tropical and is moving southeastward.

According to last ASCAT (0327Z) data, 25-30 kt winds still exist in the South of the system, mainly due to the gradient effect with the subtropical high pressures.

East of a low pressure area centered on the South of Madagascar (1006 ha), convective activity is moderate to strong from south-southeast of Madagascar to Mascarenes Islands. 0647Z ASCAT pass shows winds at about 20-25 kt off southern Madagascar. All available NWP models are in good agreement for rapid development of a low during next night or Monday morning in the area between 23S/25S and 48E/50E. Indeed, last observations of eastern coast of Madagascar (0900Z) seem to suggest a start of deepening within this area (-4.6 hPa/24h at Farafangana). This cyclogenesis seems clearly to be due to baroclinic factors (enhanced instability with a mid to upper level cold low over low level warm air). It is expected that this low gets around the southern coast of Madagascar westward and so evolves over SST in the range of 25-27C and benefits from a weak vertical wind shear under the upper level cold trough. So, it appears that this low could gain thereafter some subtropical hybrid characteristics (ie tropical and extra-tropical influences).

Regardless of the nature of this system, it should be associated with strong winds (30-35 kt and
perhaps 40 kt at least in the southern semi-circle with the gradient effect) and strong convective
activity between Madagascar and the Mascarenes islands.

For the next 36 hours, potential for development of a subtropical depression is fair to good.

Philippine Atmospherical Geophysical Astronomical Services and Administration
Tropical Cyclone Bulletin #15
TROPICAL STORM SENDONG (WASHI)
11:00 PM PhST December 18 2011
=================================

Tropical Storm "SENDONG" has moved out of The Philippine Area of Responsibility

At 10:00 PM PhST, Tropical Storm Sendong located at 10.3°N 114.3°E or 480 km west northwest of Puerto Princesa City has 10 minute sustained winds of 35 knots with gusts of 40 knots. The cyclone is reported as moving west at 12 knots.

Additional Information
========================

Fishing boats and other small sea crafts are advised not to venture out into the seaboards of Luzon and Eastern Visayas due to big waves generated by monsoon surge enhanced by TS SENDONG and extra caution must be observed over the seaboard of Western Visayas.

With this development, this is the final bulletin on this weather disturbance.

Japan Meteorological Agency
Tropical Cyclone Advisory #43
TROPICAL STORM WASHI (T1121)
3:00 AM JST December 19 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 18:00 PM UTC, Tropical Storm Washi (1000 hPa) located at 9.8N 114.3E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving west southwest at 7 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
120 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 7.2N 109.3E - Tropical Depression

Japan Meteorological Agency
Tropical Cyclone Advisory #44
TROPICAL STORM WASHI (T1121)
6:00 AM JST December 19 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 21:00 PM UTC, Tropical Storm Washi (1000 hPa) located at 9.6N 114.1E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving south southwest at 7 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
120 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 6.9N 109.2E - Tropical Depression

Japan Meteorological Agency
Tropical Cyclone Advisory #45
TROPICAL STORM WASHI (T1121)
9:00 AM JST December 19 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 0:00 AM UTC, Tropical Storm Washi (1000 hPa) located at 9.6N 113.3E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving west at 9 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
120 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 6.9N 108.9E - Tropical Depression

Japan Meteorological Agency
Tropical Cyclone Advisory #46
TROPICAL STORM WASHI (T1121)
12:00 PM JST December 19 2011
===============================

SUBJECT: Category One Typhoon in South China Sea

At 3:00 AM UTC, Tropical Storm Washi (1000 hPa) located at 9.6N 112.5E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving west at 10 knots

Dvorak Intensity: T2.5

Gale Force Winds
===============
120 NM from the center in northern quadrant
80 NM from the center in southern quadrant

Forecast and Intensity
======================
24 HRS: 6.5N 108.3E - Tropical Depression

Japan Meteorological Agency
Tropical Cyclone Advisory #47
TROPICAL DEPRESSION, FORMER WASHI
15:00 PM JST December 19 2011
===============================

SUBJECT: Tropical Depression In South China Sea

At 6:00 AM UTC, Tropical Depression, Former Washi (1004 hPa) located at 9.0N 112.0E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The cyclone is reported as moving west southwest at 10 knots

This is the final tropical cyclone advisory from the Japan Meteorological Agency

Tropical Cyclone Warning Center Brisbane
Tropical Cyclone Outlook
Forecast for the Coral Sea west of 160E
1:45 pm EST December 19 2011
===================================

A low situated southeast of Papua New Guinea is moving in a south-southwesterly direction and is expected to develop further over the next couple of days. The low is expected to remain offshore and not affect the Queensland coast.

Tropical Cyclone Formation Potential
======================================

Tuesday: Low
Wednesday: High
Thursday: High

Japan Meteorological Agency
Tropical Disturbance Summary
TROPICAL DEPRESSION, FORMER WASHI
21:00 PM JST December 19 2011
===============================

At 12:00 PM UTC, Tropical Depression, Former Washi (1004 hPa) located at 8.0N 111.0E has 10 minute sustained winds of 25 knots with gusts of 40 knots. The cyclone is reported as moving southwest at 10 knots

Seychelles Meteorological Services
Tropical Cyclone Advisory #1
DEPRESSION SUBTROPICALE 03-20112012
16:00 PM RET December 19 2011
====================================

At 12:00 PM UTC, Subtropical Depression 3 (1000 hPa) located at 25.8S 48.8E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving southwest at 6 knots

Dvorak Intensity: Nil

Forecast and Intensity
=======================
12 HRS: 26.2S 46.2E - 30 knots (Depression subtropicale)
24 HRS: 25.4S 44.1E - 30 knots (Depression subtropicale)
48 HRS: 24.2S 42.9E - 20 knots (Low Pressure Area)

Additional Information
=======================

This low shows an hybrid pattern, asymmetric without low level fronts and with a convective activity mainly sustained by a mid-level cold air (TPW below 18C from 800 HPA to 400 HPA down to 15C) and sustained also by warm and humid low level air (TPW at about 20-22C at 925 hPa). In front of an upper level trough (well defined on water vapor satellite imagery), system undergoes a strong northwesterly vertical wind shear. This area is undergoing a strong dynamical forcing in relationship with the upper level trough (stratospheric air penetrates deeply in the tropospheric cyclonic circulation - 2PVU down to 700 HPA). This stratospheric air with strong potential vortex is expected to keep on being advent towards the tropospheric mid level within the next 24 hours. Low level circulation center is expected to track globally westward and should be in phase with the upper level trough within next night. Wind shear is consequently expected to weaken. This convergence of favorable for subtropical cyclongenesis elements (sea surface temperature at 25-26C, low level warm air, mid level cold air, weak vertical wind shear. and potential vortex) should allow the system to deepen temporarily within next night before undergoing a new southerly vertical wind shear constraint tomorrow on the back of the upper level trough. Over this forecast westward track, the low cross away the southern Malagasy coastline which are expected to stay away of the strongest winds.

CURRENT INTENSITY DOES NOT JUSTIFY ISSUANCE OF REGULAR WARNINGS.

Tropical Cyclone Warning Center Darwin
Tropical Cyclone Outlook
FORECAST NORTHERN TERRITORY AREA BETWEEN 125E-142E
2:25 pm CST December 20 2011
================================================= ===

A monsoon trough near the north coast of the Top End is moving north into the Arafura Sea. A low pressure system is expected to develop in the trough within the next 12 to 24 hours and may intensify further into a tropical cyclone on Friday.

Tropical Cyclone Formation Potential
======================================

Wednesday: Low
Thursday: Moderate
Friday: High

Tropical Cyclone Warning Center Brisbane
Tropical Cyclone Outlook
Forecast for the Coral Sea west of 160E
1:45 pm EST December 20 2011
===================================

A low situated southeast of Papua New Guinea is moving in a south-southwesterly direction and is expected to develop further over the next couple of days. The low is forecast to turn southeast, away from the Queensland coast, later in the week. The low is expected to remain offshore and not directly affect the Queensland coast.

Tropical Cyclone Formation Potential
======================================

Wednesday: High
Thursday: Moderate
Friday: Moderate

Seychelles Meteorological Services
Tropical Cyclone Advisory #2
DEPRESSION SUBTROPICALE 03-20112012
10:00 AM RET December 20 2011
====================================

At 6:00 AM UTC, Subtropical Depression 3 (1004 hPa) located at 25.8S 44.8E has 10 minute sustained winds of 25 knots with gusts of 40 knots. The depression is reported as moving west at 10 knots

Dvorak Intensity: Nil

Forecast and Intensity
=======================
12 HRS: 25.5S 43.6E - 25 knots (Depression subtropicale)
24 HRS: 25.2S 42.5E - 20 knots (Low Pressure Area)

Additional Information
=======================

The system has failed to intensify, near gale force winds to very locally gale force winds still exist within a convergence line located far away form the center in the southeastern quadrant (335 NM to 535 NM from the center) due to the gradient effect with the subtropical ridge.

LAST WARNING ON THIS SYSTEM UNLESS RE-INTENSIFICATION.

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
Tropical Low 02U
11:00 PM EST December 20 2011
===================================

At 10:00 PM EST, Tropical Low 02U (1003 hPa) located at 13.7S 154.8E has 10 minute sustained winds of 25 knots with gusts of 45 knots. The low is reported as moving east northeast at 2 knots.

Dvorak Intensity: T2.0/2.0/D0.5/24 HRS

Forecast and Intensity
=======================
24 HRS: 15.3S 155.1E - 35 knots (CAT 1)
48 HRS: 17.2S 154.7E - 60 knots (CAT 2)
72 HRS: 19.2S 155.0E - 40 knots (CAT 1)

Additional Information
======================

T2.0. Convection has increased in the last few hours with diurnal trend. Organization improving slightly.

Favorable outflow in all quadrants under the influence of an upper atmospheric anticyclone. No significant wind shear expected over the next 2 days before an upper trough should impact the system on Friday. As a result the system is expected to develop over the next 48 hours and move to the south-southeast on Wednesday and Thursday, before experiencing increasing wind shear and steering
to the southeast.

The next tropical cyclone update from Brisbane Tropical Cyclone Warning Center will be issued at around 19:00 PM UTC..

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
Tropical Low 02U
5:00 AM EST December 21 2011
===================================

At 4:00 AM EST, Tropical Low 02U (1000 hPa) located at 14.1S 155.7E has 10 minute sustained winds of 25 knots with gusts of 45 knots. The low is reported as moving east southeast at 5 knots.

Dvorak Intensity: T2.0/2.0/D0.5/24HRS

Forecast and Intensity
=======================
24 HRS: 16.3S 156.5E - 35 knots (CAT 1)
48 HRS: 18.4S 156.7E - 60 knots (CAT 2)
72 HRS: 19.9S 157.4E - 35 knots (CAT 1)

Additional Information
======================

Dvorak analysis based on a curved band pattern with 0.3 degree wrap, giving DT of 2.0. MT and PT agree. FT based on MT as DT is not clear.

Organisation has improved slightly and convection has consolidated in the vicinity of the low in the last 24 hours. The low appears to be in a favorable environment for development with low wind shear and sea surface temperatures around 30 degrees.

However, an upper trough is expected to amplify across eastern Australia on Thursday, which will increase the wind shear across the low into Friday. The increase in the wind shear is likely to hinder development from Friday onwards, though computer model guidance indicates that intensification may still occur while the system possibly undergoes extra tropical transition.

The next tropical cyclone bulletin from Brisbane Tropical Cyclone Warning Center will be issued at around 1:00 AM UTC..

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
Tropical Low 02U
11:00 AM EST December 21 2011
===================================

At 10:00 AM EST, Tropical Low 02U (1000 hPa) located at 15.0S 156.6E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The low is reported as moving southeast at 9 knots.

Dvorak Intensity: T2.5/2.5/D1.0/24HRS

Forecast and Intensity
=======================
24 HRS: 17.6S 157.4E - 45 knots (CAT 1)
48 HRS: 19.7S 157.4E - 50 knots (CAT 2)
72 HRS: 20.5S 158.7E - 40 knots (CAT 1)

Additional Information
======================

Dvorak analysis based on a curved band pattern with 0.3 degree wrap, giving DT of 2.0. MT and PT give 2.5. FT based on MT as DT is not clear.

Organisation has improved significantly and convection has consolidated in the vicinity of the low in the last 24 hours. The low appears to be in a favorable environment for development with low wind shear and sea surface temperatures around 30 degrees.

However, an upper trough is expected to amplify across eastern Australia on Thursday, which will increase the wind shear across the low into Friday. The increase in the wind shear is likely to hinder development from Friday onwards, though computer model guidance indicates that intensification may still occur while the system possibly undergoes extra tropical transition.

The next tropical cyclone bulletin from Brisbane Tropical Cyclone Warning Center will be issued at 7:00 AM UTC..

Tropical Cyclone Warning Center Darwin
Tropical Cyclone Outlook
FORECAST NORTHERN TERRITORY AREA BETWEEN 125E-142E
2:15 pm CST December 21 2011
================================================= ===

A developing tropical low is located north of the Top End in the Arafura Sea. The low is expected to remain slow moving and intensify gradually. The low may develop into a tropical cyclone late Friday.

Tropical Cyclone Formation Potential
======================================

Thursday: Low
Friday: High
Saturday: High

Perth Tropical Cyclone Warning Center
Tropical Cyclone Outlook
FORECAST WESTERN AUSTRALIA REGION BETWEEN 90E-125E SOUTH OF 10S
12:33 PM WST December 21 2011
=========================

A low is developing near 07S 92E, outside of the Western Region. This low is likely to enter the Western Region during Friday or Saturday and may develop into a tropical cyclone during Saturday to the west of Cocos Island.

Tropical Cyclone Formation Potential
===================================

Thursday: Very Low
Friday: Low
Saturday: Moderate

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
Tropical Low 02U
5:00 PM EST December 21 2011
===================================

At 4:00 PM EST, Tropical Low 02U (1001 hPa) located at 16.1S 157.1E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The low is reported as moving southeast at 12 knots.

Dvorak Intensity: T2.0/2.5/W0.5/6 HRS

Forecast and Intensity
=======================
24 HRS: 18.6S 157.1E - 40 knots (CAT 1)
48 HRS: 20.9S 156.8E - 35 knots (CAT 1)
72 HRS: 20.5S 158.7E - 30 knots (Tropical Low)

Additional Information
======================

Dvorak analysis based on a curved band pattern with 0.35 degree wrap, giving DT of 2.0. MT and PT give 2.0. FT based on MT as DT is not clear. CI held at 2.5.

Overnight convection has sheared off with persistent convection remaining near the LLCC. CIMSS analysing 20 knots of shear over the system which is likely the cause for lack of development. Models hinting at similar shear for the next 36-48 hours. Slow development is still considered likely over this period with inflow/outflow favorable.

An upper trough is expected to amplify across eastern Australia on Thursday, which will increase the wind shear across the low into Friday. The increase in the wind shear is likely to steer the system east-southeast and hinder development from Friday onwards. Computer model guidance indicates that intensification due to extra-tropical transition may occur over this period.

The next tropical cyclone bulletin from Brisbane Tropical Cyclone Warning Center will be issued at 13:00 PM UTC..

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
Tropical Low 02U
11:00 PM EST December 21 2011
===================================

At 10:00 PM EST, Tropical Low 02U (998 hPa) located at 17.1S 157.4E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The low is reported as moving south southeast at 11 knots.

Dvorak Intensity: T2.5/2.5/D0.5/24 HRS

Forecast and Intensity
=======================
24 HRS: 19.3S 157.0E - 40 knots (CAT 1)
48 HRS: 21.4S 157.2E - 30 knots (Tropical Low)
72 HRS: 21.4S 159.7E - 30 knots (Tropical Low)

Additional Information
======================

Dvorak analysis FT 2.5 based on MET and PAT.

Persistent convection this afternoon has increased over the last few hours, probably coincident with a decrease in shear from CIMSS to between 10 and 20 knots. 0806UTC TMI 37GHz image shows reasonable banding and organisation in the low levels. Good outflow to the southeast with northwest shear still over the system. Models hinting at similar shear for the next 36-48 hours. Slow development is forecast over this period and the system is considered likely to become a tropical cyclone on Thursday morning.

An upper trough is expected to amplify across eastern Australia on Thursday, which will increase the wind shear across the low into Friday. The increase in the wind shear is likely to steer the system east-southeast and hinder tropical development from Friday onwards. Computer model guidance indicates that intensification due to extra-tropical transition may occur over this period.

The next tropical cyclone bulletin from Brisbane Tropical Cyclone Warning Center will be issued at 19:00 PM UTC..

Darwin Tropical Cyclone Warning Center
Tropical Cyclone Advice #2
Tropical Low 04U
11:00 PM CST December 21 2011
===================================

At 9:30 PM CST, Tropical Low 04U (1001 hPa) located at 9.6S 132.3E or 175 km north of Croker Island and 350 km north northeast of Darwin has 10 minute sustained winds of 20 knots with gusts of 45 knots. The low is reported as moving west northwest at 1 knot.

Dvorak Intensity: T1.5

A tropical cyclone is expected to develop late on Friday or during Saturday north of the Top End. GALES are not expected in coastal areas in the next 24 hours, however gales could develop later.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Residents of Darwin and Rural Area are advised that if you DO NOT have accommodation constructed to the Building Code or are unsure of your present accommodation you should determine which public emergency shelter to use. This advice is issued to allow you sufficient time in which to take the necessary precautions before winds reach a dangerous level.

Tropical Cyclone Watch
=====================

A Cyclone WATCH is current for a developing tropical low for coastal areas from Dundee Beach to Nhulunbuy, including Darwin.

Forecast and Intensity
======================

24 HRS: 9.0S 132.7E - 30 knots (Tropical Low)
48 HRS: 10.1S 133.1E - 40 knots (CAT 1)
72 HRS: 10.6S 132.0E - 60 knots (CAT 2)

Additional Information
======================

Persistence used as key determinant for current position - rotation evident in IR further to the west appears to be associated remnant mid level cloud from earlier convection. Recent storm activity hints at consolidation near previous position.

Upper level trough passage to south in 24 to 48 hours, together with low level easterly burst is expected to produce mostly favorable conditions suited for rapid development of a small system. Unidirectional nature of upper flow may be a limiting factor for a period until the trough relaxes sufficiently to allow the upper high to consolidate.

Widely varying model guidance, with little intra run or intra model consistency, suggests a conservative forecast policy is warranted. Longer term motion could be ESE driven by capture of the mid to upper level trough, or by subsequent post trough ridging, forcing a WSW track.

The WSW track in the 48 to 96 hour time frame is favored at present, though warning policy continues to allow for the alternate possibility.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 19:00 PM UTC..

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
TROPICAL CYCLONE FINA (02U)
5:00 AM EST December 22 2011
===================================

At 4:00 AM EST, Tropical Cyclone Fina, Category One (996 hPa) located at 17.5S 157.2E or 1110 km east of Townsville and 940 km east northeast of Mackay has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving south at 10 knots.

Dvorak Intensity: T3.0/3.0/D0.5/24 HRS

Gale Force Winds
===============
120 NM from the center

Forecast and Intensity
=======================
24 HRS: 19.5S 156.0E - 30 knots (Tropical Low)
48 HRS: 21.6S 156.5E - 30 knots (Tropical Low)
72 HRS: 21.9S 159.7E - 30 knots (Tropical Low)

Additional Information
======================

Dvorak analysis based on a shear pattern with less than 0.5 degree separation between the estimated location of the low level center and the dense overcast, giving DT of 3.0. MT and PT suggest 2.5. FT based on DT and supporting ASCAT wind observations at 1127UTC.

Increasing shear has begun to impact on Tropical Cyclone Fina due to an amplifying upper trough across eastern Australia. This increasing shear is expected to continue impacting on Fina as it moves in a southerly direction and should limit any further development. However, computer model guidance indicates that intensification could still be possible due to extra-tropical transition that may occur into Friday. Gale force winds are possible on Friday as this transition occurs and a surge of southeasterly winds feed into the south of the
system.

The next tropical cyclone bulletin from Brisbane Tropical Cyclone Warning Center will be issued at 1:00 AM UTC.

Darwin Tropical Cyclone Warning Center
Tropical Cyclone Advice #3
Tropical Low 04U
4:00 AM CST December 22 2011
===================================

At 3:30 AM CST, Tropical Low 04U (1000 hPa) located at 9.8S 132.4E or 150 km north of Croker Island and 335 km north northeast of Darwin has 10 minute sustained winds of 20 knots with gusts of 45 knots. The low is reported as moving south at 1 knot.

Dvorak Intensity: T1.5/1.5/S/12 HRS

A tropical cyclone is expected to develop late on Friday or during Saturday north of the Top End. GALES are not expected in coastal areas in the next 24 hours, however gales could develop later.

A tropical cyclone is expected to develop early Saturday north of the Top End. GALES are not expected in coastal areas in the next 24 hours, however gales could develop later.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Residents of Darwin and Rural Area are advised that if you DO NOT have accommodation constructed to the Building Code or are unsure of your present accommodation you should determine which public emergency shelter to use. This advice is issued to allow you sufficient time in which to take the necessary precautions before winds reach a dangerous level.

Tropical Cyclone Watch
=====================

A Cyclone WATCH is current for a developing tropical low for coastal areas from Dundee Beach to Nhulunbuy, including Darwin.

Forecast and Intensity
======================

24 HRS: 9.9S 132.2E - 30 knots (Tropical Low)
48 HRS: 10.8S 132.4E - 35 knots (CAT 1)
72 HRS: 11.0S 131.6E - 50 knots (CAT 2)

Additional Information
======================

The monsoon trough has been active tonight with deep convection aligned with the trough across the Arafura Sea. While a broad mid level circulation can be observed in IR imagery, locating the low level system centre is proving difficult. Persistence and the location of new storm activity is used as key determinant for current position.

Upper level trough passage to south in 24 to 48 hours, together with low level easterly burst is expected to produce mostly favorable conditions for development.

Movement of the system has been slow with westerly flow coming across the Equator and easterly flow from the continent finely balanced. Model guidance remains highly variable, with little intra run or intra model consistency, which suggests a conservative forecast policy is warranted. While some models are capturing the system in the mid to upper level trough and bringing it east briefly, others keep the system slow moving until the ridge over the continent pushes in and send the system west.

The WSW track in the 48 to 96 hour time frame is favoured at present, though warning policy continues to allow for the alternate possibility.

Dvorak classification remains at 1.5 due to constraints.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 1:00 AM UTC..

based on the photo above. It is a character from one of the 35 series television show called "Super Sentai" in Japan.

Tropical Low 04U forecast map from Darwin Tropical Cyclone Warning Center

Google Earth image of Tropical Low 04U.

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
TROPICAL CYCLONE FINA (02U)
11:00 AM EST December 22 2011
===================================

At 10:00 AM EST, Tropical Cyclone Fina, Category One (995 hPa) located at 18.5S 156.0E or 770 km east northeast of Mackay and 790 km northeast of Rockhampton has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving southwest at 10 knots.

Dvorak Intensity: T2.0/3.0/W1.5/24 HRS

Gale Force Winds
===============
120 NM from the center

Forecast and Intensity
=======================
24 HRS: 21.1S 155.3E - 30 knots (Tropical Low)
48 HRS: 22.7S 156.8E - 30 knots (Tropical Low)
72 HRS: 22.7S 158.6E - 30 knots (Tropical Low)

Additional Information
======================

Dvorak analysis based on a shear pattern with approximately 2 degrees of separation between the low level center and the dense overcast, giving DT of 1.0. MT and PT agree. FT based on Dvorak rules.

Increasing shear began impacting on Tropical Cyclone Fina overnight due to an amplifying upper trough across eastern Australia. This increasing shear is expected to continue impacting on Fina as it moves in a southwesterly direction and should limit any further development. However, computer model guidance indicates that re-intensification and gale force winds are likely during Friday as the system begins to interact with a firm ridge of high pressure situated across the southern Coral Sea.

The next tropical cyclone bulletin from Brisbane Tropical Cyclone Warning Center will be issued at 7:00 AM UTC.

Darwin Tropical Cyclone Warning Center
Tropical Cyclone Advice #4
Tropical Low 04U
10:00 AM CST December 22 2011
===================================

At 9:30 AM CST, Tropical Low 04U (1000 hPa) located at 10.0S 132.5E or 130 km north of Croker Island and 320 km north northeast of Darwin has 10 minute sustained winds of 20 knots with gusts of 45 knots. The low is reported as moving south at 2 knots.

Dvorak Intensity: T1.0/1.5/D0.5/24 HRS

A tropical cyclone is expected to develop early Saturday north of the Top End. GALES are not expected in coastal areas in the next 24 hours, however gales could develop later.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Residents of Darwin and Rural Area are advised that if you DO NOT have accommodation constructed to the Building Code or are unsure of your present accommodation you should determine which public emergency shelter to use. This advice is issued to allow you sufficient time in which to take the necessary precautions before winds reach a dangerous level.

Tropical Cyclone Watch
=====================

A Cyclone WATCH is current for a developing tropical low for coastal areas from Dundee Beach to Nhulunbuy, including Darwin

Forecast and Intensity
======================

24 HRS: 10.1S 132.2E - 25 knots (Tropical Low)
48 HRS: 10.9S 132.3E - 40 knots (CAT 1)
72 HRS: 11.3S 131.4E - 50 knots (CAT 2)

Additional Information
======================

The monsoon trough has remained active with more focused convection along the trough axis. The low level system center location is poor based on latest visible imagery and surface observations. System remains poorly defined in deep convection, with a weak sense of curvature with 0.2 wrap suggesting DT 1.0/1.5. FT based on PT of 1.0.

Upper level trough to west, together with low level easterly burst is expected to produce favorable conditions for development.

Movement of the system has been slow with westerly flow coming across the Equator and easterly flow from the continent finely balanced. Model guidance remains highly variable, with little intra run or intra model consistency, which suggests a conservative forecast policy is warranted. While some models are capturing the system in the mid to upper level trough and bringing it east, others keep the system slow moving until the mid-level ridge over the continent pushes in and sends the system west.

The WSW track in the 48 to 96 hour time frame is favored at present, though warning policy continues to allow for the alternate possibility.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 7:30 AM UTC..

Brisbane Tropical Cyclone Warning Center
Tropical Cyclone Bulletin
TROPICAL LOW, FORMER FINA (02U)
12:00 PM EST December 22 2011
===================================

At 11:00 AM EST, Tropical Low, Former Fina (998 hPa) located at 18.9S 155.8E or has 10 minute sustained winds of 35 knots with gusts of 50 knots. The low is reported as moving south southwest at 11 knots.

Dvorak Intensity: T2.0/2.5/W1.5/24 HRS

Gale Force Winds
===============
90 NM in southeast quadrant

Forecast and Intensity
=======================
24 HRS: 21.4S 155.2E - 30 knots (Tropical Low)
48 HRS: 22.9S 156.8E - 30 knots (Tropical Low)
72 HRS: 22.8S 158.5E - 30 knots (Tropical Low)

Additional Information
======================

Dvorak analysis based on a shear pattern with greater than 2 degrees of separation between the low level center and the existing dense overcast, giving DT of 1.0. MT and PT agree. FT 2.0 based on Dvorak rules with CI of 2.5.

Increasing shear began impacting on this system overnight due to an amplifying upper trough across eastern Australia. This increasing shear is expected to continue impacting on the system as it moves in a south-southwesterly direction and should limit any further development.

The 22:35Z Ascat image confirms the system has lost most of its structure, with near gales persisting in the southeast quadrant only. Recent VIS satellite images show some convection developing on the southeast quadrant, but given CIMSS shear values between 20 and 30 knots, this is considered a product of baroclinic or extra-tropical development.

Computer model guidance indicates that re-intensification into an extra-tropical low with associated gale force winds is likely during Friday as the system begins to interact with a firm ridge of high pressure situated across the southern Coral Sea.

No further tropical cyclone bulletins will issued for this system unless re-generation occurs.

Perth Tropical Cyclone Warning Center
Tropical Cyclone Outlook
FORECAST WESTERN AUSTRALIA REGION BETWEEN 90E-125E SOUTH OF 10S
1:34 PM WST December 22 2011
=========================

A low is developing near 9S 92E, outside of the Western Region. This low is likely to enter the Western Region during Friday or Saturday and may develop into a tropical cyclone on Saturday or Sunday, to the west of Cocos Island. The system is likely to move southwest out of the Western Region during Sunday.

Tropical Cyclone Formation Potential
===================================

Friday: Low
Saturday: Moderate
Sunday: Moderate

Darwin Tropical Cyclone Warning Center
Tropical Cyclone Advice #5
Tropical Low 04U
4:00 PM CST December 22 2011
===================================

At 3:30 PM CST, Tropical Low 04U (999 hPa) located at 10.2S 132.0E or 125 km north northwest of Croker Island and 275 km north northeast of Darwin has 10 minute sustained winds of 20 knots with gusts of 45 knots. The low is reported as moving west at 2 knots.

Dvorak Intensity: T1.0/1.0/S/6 HRS

A tropical cyclone is expected to develop early Saturday north of the Top End. GALES are not expected in coastal areas in the next 24 hours, however gales could develop later.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Residents of Darwin and Rural Area are advised that if you DO NOT have accommodation constructed to the Building Code or are unsure of your present accommodation you should determine which public emergency shelter to use. This advice is issued to allow you sufficient time in which to take the necessary precautions before winds reach a dangerous level.

Tropical Cyclone Watch
=====================

A Cyclone WATCH is current for a developing tropical low for coastal areas from Dundee Beach to Nhulunbuy, including Darwin.

Forecast and Intensity
======================

24 HRS: 10.5S 131.8E - 30 knots (Tropical Low)
48 HRS: 11.0S 131.5E - 40 knots (CAT 1)
72 HRS: 11.6S 130.0E - 55 knots (CAT 2)

Additional Information
======================

The low level system center location is poor, based on latest visible imagery and surface observations. Any convection that is developing near the center is advecting away from the system, indicating there is no mid level circulation associated with the system. Model analyses suggest that a shear line extends over the system at both 700 and 500 hPa, rather than a discrete circulation

Given the lack of deep convection near the center the intensity analysis is held at the bare minimum.

Surface pressures continue to drop by about 2 hPa per day, and upper level diffluent flow is evident as a mid and upper level trough passes to the south. Guidance does suggest that eventually the circulation will extend in depth over the next 24 to 48 hours, however the system is still likely to be 36 to 60 hours away from reaching TC intensity.

Two models have suggested in recent runs that capture in the monsoon flow to the north and a resultant track to the SE remain possible, however the consensus from the remaining models is that the system will steer to the WSW or SW for a period as the mid level ridge briefly builds in the wake of the mobile trough. This is the preferred solution.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 13:30 PM UTC..

Darwin Tropical Cyclone Warning Center
Tropical Cyclone Advice #6
Tropical Low 04U
10:00 PM CST December 22 2011
===================================

At 9:30 PM CST, Tropical Low 04U (999 hPa) located at 10.3S 130.7E or 230 km west northwest of Croker Island and 235 km north of Darwin has 10 minute sustained winds of 20 knots with gusts of 45 knots. The low is reported as moving west at 3 knots.

Dvorak Intensity: T1.0/1.0/S/12 HRS

A tropical cyclone is expected to develop during Saturday north of the Top End. GALES are not expected in coastal areas in the next 24 hours, however gales could develop later.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Residents of Darwin and Rural Area are advised that if you DO NOT have accommodation constructed to the Building Code or are unsure of your present accommodation you should determine which public emergency shelter to use. This advice is issued to allow you sufficient time in which to take the necessary precautions before winds reach a dangerous level.

Tropical Cyclone Watch
=====================

A Cyclone WATCH is current for a developing tropical low for coastal areas from Dundee Beach to Nhulunbuy, including Darwin.

Forecast and Intensity
======================

24 HRS: 10.5S 130.4E - 25 knots (Tropical Low)
48 HRS: 11.1S 130.4E - 35 knots (CAT 1)
72 HRS: 11.6S 129.7E - 50 knots (CAT 2)

Additional Information
======================

Convection has redeveloped in the vicinity of a candidate low level center. However mid level cloud features continue to stream past in the NW monsoon flow, indicative of a shear line persisting in the mid levels. For this candidate LLC to develop further the mid shear line needs to evolve into a more vertically aligned circulation structure.

Surface pressures continue to drop by about 2 hPa per day, and upper level diffluent flow is evident [though weaker than at the time of the previous advice] as a mid and upper level trough passes to the south.

Given the lack of continuous deep convection near the center the intensity analysis is held at the bare minimum.

Guidance does suggest that eventually the circulation will extend in depth over the next 24 to 48 hours, however the system is still likely to be 36 to 60 hours away from reaching TC intensity, at the earliest.

The has been an increase in the number of models promoting a track to the SE in the 0000z cohort of forecasts. However the candidate LLC center is further west than those initialized in these runs. Given the lack of any consistency between models, and between successive model runs, a conservative approach continues to be followed in forecast policy. The possibility remains that the verifying solution will be different again to that which is suggested by the current model scenarios.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 19:30 PM UTC..

Darwin Tropical Cyclone Warning Center
Tropical Cyclone Advice #7
Tropical Low 04U
4:00 AM CST December 23 2011
===================================

At 3:30 AM CST, Tropical Low 04U (999 hPa) located at 10.3S 130.7E or 125 km north of Snake Bay and 235 km north of Darwin has 10 minute sustained winds of 20 knots with gusts of 45 knots. The low is reported as nearly stationary

Dvorak Intensity: T1.0/1.0/S0.0/18 HRS

A tropical cyclone is expected to develop during Sunday north of the Top End. GALES are not expected in coastal areas in the next 24 hours, however gales could develop later.

The Territory Controller advises communities under Watch that now is the time to put together your emergency kit, clear your yards and balconies, and commence home shelter preparations.

Residents of Darwin and Rural Area are advised that if you DO NOT have accommodation constructed to the Building Code or are unsure of your present accommodation you should determine which public emergency shelter to use. This advice is issued to allow you sufficient time in which to take the necessary precautions before winds reach a dangerous level.

Tropical Cyclone Watch
=====================

A Cyclone WATCH is current for a developing tropical low for coastal areas from Dundee Beach to Nhulunbuy, including Darwin.

Forecast and Intensity
======================

24 HRS: 10.5S 130.6E - 25 knots (Tropical Low)
48 HRS: 10.8S 130.5E - 35 knots (CAT 1)
72 HRS: 11.5S 130.3E - 50 knots (CAT 2)

Additional Information
======================

Convection has redeveloped near the center of a low level center north of the Tiwi Islands, but remains disorganized. However mid level cloud features continue to stream past in the NW monsoon flow, indicative of a shear line persisting in the mid levels. For this candidate LLC to develop further the mid shear line needs to evolve into a more vertically aligned circulation structure. Most recent animated satellite imagery suggests another circulation may be located further east, north of Cobourg Peninsula.

Strongest surface pressures falls are currently located near the Cobourg Peninsula. In general, pressures continue to drop by about 2 hPa per day, upper level diffluent flow is evident [though weaker than at the time of the previous advice] as a mid and upper level trough passes to the south.

Given the lack of continuous deep convection near the center the intensity analysis is held at the bare minimum. Dvorak analysis yields a 0.2 wrap on a curved band to the west. FT is based on DT.

Guidance does suggest that eventually the circulation will extend in depth over the next 24 to 48 hours, however the system is still likely to be 36 to 60 hours away from reaching TC intensity.

Movement is forecast to be slow in the next 24 to 48 hours.

There has been an increase in the number of models promoting a track to the SE in the 00Z and available 12Z cohort of forecasts. However the candidate LLC center is further west than those initialized in these runs. Given the lack of any consistency between models, and between successive model runs, a conservative approach continues to be followed in forecast policy. The possibility remains that the verifying solution will be different again to that which is suggested by the current model scenarios.

The next tropical cyclone bulletin from Darwin Tropical Cyclone Warning Center will be issued at 1:30 AM UTC..